Is there a way to reduce the amount of audio files needed to have spoken lines in renpy? When I have done it I needed a new file for every line, can you fetch lines from a single file?
No, all lines have to be individual files for each line. You can save space by using a file format like .ogg however. That's what I use. Audacity can make those. I'd save it at a quality no lower than 5 if you want to save space.